Tubular Adenoma of the Colon: Symptoms, Causes, Diagnosis and Treatment — What You Need to Know
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Editorial note: This article is provided for educational purposes only. It is not medical advice. If you notice blood in your stool, changes in bowel habits, or abdominal pain, seek prompt medical evaluation, and always consult a qualified healthcare professional about your individual situation.
Quick Answer: What is a tubular adenoma?
A tubular adenoma is a type of colon polyp, a benign but precancerous growth on the lining of the large intestine that can slowly become cancer if not removed [1]. It is the most common adenoma found during colonoscopy and carries the lowest cancer risk [1]. It is removed during colonoscopy, followed by surveillance colonoscopies timed to the findings [2].
What the research says
Type 2 diabetes raises the odds of colorectal adenomas. Pooling 17 studies with 28,999 participants and 6,798 adenoma cases, type 2 diabetes was linked to a higher risk of colorectal adenoma (RR 1.52, 95% CI 1.29–1.80) and of advanced adenoma (RR 1.41, 95% CI 1.06–1.87). The link was not significant in prospective studies alone (Yu et al., BMC Cancer, 2016) [3].
Adenomas are not only a problem after 50. In 24 studies of 23,142 people aged 18–49, about 9.0% (95% CI 7.1–11.4%) had an adenoma, and 6.0% (95% CI 4.1–8.6%) developed advanced neoplasia on follow-up colonoscopy after a young-onset adenoma. The authors noted that no studies had tested whether routine surveillance lowers cancer risk in this age group (Enwerem et al., Clinical Gastroenterology and Hepatology, 2021) [4].
When should you seek prompt medical evaluation for a tubular adenoma?
Most tubular adenomas of the colon cause no symptoms [1], which is why routine colon cancer screening matters so much. However, if you notice any of the following changes, seek prompt medical evaluation to rule out colon cancer:
Regular colon cancer screening and complete removal of all adenomas are the best ways to prevent colon cancer from developing.
What Exactly Is a Tubular Adenoma?
A tubular adenoma is a type of colon polyp that forms on the inner lining of the large intestine. It is the most common type of adenoma found during colonoscopy [1] and is considered precancerous — meaning it can slowly change into colon cancer over time if it's not removed [1].
The word "adenoma" matters: an adenoma is one type of colon polyp, so all adenomas are polyps. But not all polyps are adenomas. Each polyp type has its own features and level of cancer risk [1].
Tubular adenomas are defined by their microscopic structure: round, tube-shaped glands. This structure carries the lowest cancer risk among adenoma types [1]. By contrast, villous adenomas have longer, fingerlike projections and a higher cancer risk [1], while tubulovillous adenomas show features of both and also carry a high risk [1].
All adenomas show dysplasia — cells growing in an irregular pattern. Low-grade dysplasia represents early, mild change. High-grade dysplasia means an area has more-serious precancerous growth and requires more-frequent monitoring [1].
A tubular adenoma is benign — not cancer. But it has the potential to develop into adenocarcinoma (a type of cancer). That's why it should be removed when found and monitored through follow-up colonoscopy [1].
What Are the Symptoms of a Tubular Adenoma?
Most tubular adenomas do not cause symptoms. They grow very slowly and are often discovered during a routine screening colonoscopy [1] before they cause any problems. Most people with tubular adenomas feel well and have no warning signs. Finding and removing these adenomas early is one of the main reasons colon cancer screening is so effective [1].
That said, certain changes can be signs that require prompt medical evaluation — not because they confirm a polyp, but because they need to be checked to rule out colon cancer:
What Causes a Tubular Adenoma?
The exact cause of tubular adenomas is not fully known. They develop when the lining of the colon begins to grow faster than usual [1]. Over time, this extra growth can form a polyp. Most tubular adenomas start as tiny clusters of cells that gradually enlarge over many years [1].
What Increases the Risk of Developing a Tubular Adenoma?
Any person can develop a tubular adenoma or another type of polyp in the colon. However, several factors make them more likely:
Risk factor | What to know |
Age | Most people with colon polyps are 50 or older [1] |
Intestinal conditions | Inflammatory bowel disease (ulcerative colitis or Crohn's disease) raises the overall risk of polyps and colorectal cancer [1] |
Family history | A parent, sibling, or child with advanced colon polyps (10 mm or larger in diameter) increases your risk; the more family members affected, the greater the risk [1] |
Personal history | Previous colon polyps are a risk factor for forming new polyps [1] |
Smoking and alcohol | Three or more alcoholic drinks a day increases polyp risk; combining alcohol with smoking also increases risk [1] |
Diabetes | Increases polyp risk by 50% among all age groups [1] |
Lifestyle | Overweight, less healthy diet, and lack of regular exercise increase risk [1] |
Race and ethnicity | In the U.S., Native American and Alaska Native people have the highest colorectal cancer rates, followed by African American men and women; Ashkenazi Jews have one of the highest colorectal cancer risks of any ethnic group worldwide [1] |
Inherited syndromes | Rare gene changes — such as Lynch syndrome and familial adenomatous polyposis (FAP) — cause polyps to form and increase colorectal cancer risk [1] |
Having one or more risk factors does not mean you will definitely develop a tubular adenoma [1]. But it may increase the importance of regular colonoscopy screening and healthy lifestyle habits.
How Does a Tubular Adenoma Differ From Other Polyps?
Polyp type | Microscopic appearance | Precancerous? | Cancer risk | Notes |
Tubular adenoma | Tube-shaped glands | Yes | Low | Most common adenoma; grows slowly; lowest cancer risk among adenomas [1] |
Villous adenoma | Long, fingerlike projections | Yes | High | Less common; highest chance of becoming cancer if untreated |
Tubulovillous adenoma | Mix of tube and fingerlike glands | Yes | High | Features of both; high risk if not removed |
Serrated adenoma | Saw-toothed gland pattern | Yes | Variable | Different growth pathway [1]; still precancerous |
Hyperplastic polyp | Flat or saw-toothed surface | No | Very low | Common, especially in rectum and sigmoid colon [1]; usually harmless |
Inflammatory polyp | Irregular, inflamed tissue | No | None | Forms with long-term inflammation [1] (e.g., IBD); not a true adenoma |
Hamartomatous polyp | Disorganized normal tissue | Sometimes | Slightly increased if multiple or genetic cause | Usually not cancerous; can appear with inherited syndromes [1] |
How Is a Tubular Adenoma Diagnosed?
Most tubular adenomas are found during routine screening — such as colonoscopy — rather than because of symptoms [2]. During a colonoscopy, a healthcare professional uses a long, flexible tube attached to a video camera to view the whole colon and rectum on a video monitor [2].
If any small growths (polyps) are seen, they can often be removed right then. This is important because while most polyps are not cancerous, some can develop into cancer over time [2].
The team can sometimes see surface patterns during the colonoscopy using special imaging techniques — for example, brown slits within the glands can suggest the polyp is a tubular adenoma [2]. But the final diagnosis comes from examining the tissue under a microscope (histopathology), performed by a pathologist [2].
What Does Your Pathology Report Mean?
A pathology report for a tubular adenoma describes what a pathologist saw when examining the removed polyp under a microscope. Here are the common terms you'll see:
Report term | What it means |
Type of polyp | "Tubular adenoma" means benign (not cancer) but precancerous — potential to become cancer over time if not removed |
Size and location | How large the polyp was and where in the colon or rectum it was found |
Histologic findings | What the tissue looks like under the microscope — tubular adenomas have a tubelike gland structure |
Dysplasia grade | Low-grade = early/mild cell changes, cancer risk very low when completely removed. High-grade (or focal high-grade) = more-advanced precancerous change, but not cancer; complete removal eliminates the risk [2] |
Margin status | Negative margin = edges are free of unusual cells (complete removal). Positive margin = suspicious cells remain [2] (may need further treatment) |
High-risk features | Larger size, multiple adenomas, villous (fingerlike) features, or high-grade dysplasia [2] |
Follow-up recommendation | Summary note on what the findings mean and when to return for another colonoscopy |
When Should You Have Your Next Colonoscopy?
The timing of your next colonoscopy after a tubular adenoma is removed depends on the number, size and features of the polyps found [2].
How Is a Tubular Adenoma Treated?
The main treatment is polypectomy — removing the adenoma during a colonoscopy. A healthcare professional guides an endoscope (a long, flexible tube with a light, camera, and tiny surgical tools) through the colon. A wire loop called a snare cuts the adenoma away [2]. The procedure is quick, generally painless, and performed under sedation [2].
Once removed, the tissue is sent to a lab to confirm the entire polyp was taken out and to check for dysplasia or other high-risk features [2].
Can Tubular Adenomas Come Back?
If a polyp is not completely removed — for example, if cells or tissue are inadvertently left behind — it can regrow in the same location [2]. After removing large polyps, especially by piecemeal approach, a second colonoscopy may be scheduled within 3 to 6 months to carefully reinspect the area [2].
After complete removal, the same polyp does not grow back [2]. But new adenomas can form over time [2]. This is why follow-up colonoscopies are so important — they help find and remove new polyps before they can cause harm.
When Does a Tubular Adenoma Become Cancer?
A tubular adenoma becomes cancer only if its cells continue to grow and change over many years without being removed [2]. The risk is very low once a polyp has been taken out completely [2]. Adenomas that are large, contain high-grade dysplasia, or have villous features are more likely to progress if left untreated [2].
Stool-based screening tests — such as multitarget stool DNA testing — can identify many large polyps and most high-grade polyps [2]. A positive stool test does not by itself indicate a polyp or cancer; a colonoscopy must be performed to evaluate anyone with a positive result [2].
How Should You Prepare for Your Follow-Up Appointment?
If you've been told you have a tubular adenoma, you'll likely be referred to specialists: a gastroenterologist (digestive disease specialist), a colorectal surgeon, and/or a pathologist [2].
Before the appointment:
Ask a trusted family member or friend to come with you [2] — they can help you remember what the healthcare team says and provide emotional support
List any symptoms you have and when they began [2]
Gather key medical information: other health conditions, and any family history of colon polyps or colon cancer [2]
List all medicines, vitamins, and supplements you take, including doses [2]
Write down your questions
Questions to ask your doctor:
Where in my colon was the tubular adenoma found?
How large was it, and was it completely removed?
Did the pathology report show low-grade or high-grade dysplasia?
How often should I have follow-up colonoscopies?
What is my risk of developing new adenomas or colon cancer?
Are there changes I can make to lower my risk, such as diet or lifestyle habits?
Will I need to see a specialist again before my next screening?
Can I have a copy of my pathology report for my records?
Are there any educational materials or websites you recommend?
What your doctor will ask you:
Have you ever had colon polyps before?
Do you have a family history of colon cancer or polyps?
Have you noticed any blood in your stool or other bowel changes?
Have you ever had a colonoscopy or stool test before this one?
Do you have any chronic health conditions, such as inflammatory bowel disease?
Conclusion: A Tubular Adenoma Is Precancerous — But Highly Manageable
A tubular adenoma diagnosis sounds alarming, but the facts are reassuring. It is not cancer. It is the adenoma type with the lowest cancer risk. And it is typically removed in a single, quick, sedated procedure — often during the same colonoscopy where it was found.
The key messages: complete removal eliminates the risk of that polyp turning into cancer. The same polyp does not grow back once fully removed. Your follow-up schedule — whether that's 1 year, 3 years, 3–5 years, or 7–10 years — is tailored to your specific pathology findings, and following it is the best protection against new adenomas forming silently.
Your next step: If your colonoscopy or stool screening found a tubular adenoma, ask for a copy of your pathology report, confirm your follow-up colonoscopy date, and discuss any lifestyle changes (diet, exercise, alcohol reduction, smoking cessation) that can lower your risk of new polyps. If you're 45 or older and haven't been screened for colon cancer, talk to your healthcare provider about scheduling screening — most adenomas cause no symptoms, and screening is what catches them early.
Related reading: Colon Cancer | Crohn's Disease | Familial Adenomatous Polyposis (FAP)
Sources: Mayo Clinic — Tubular Adenoma of the Colon: Symptoms & Causes | Mayo Clinic — Tubular Adenoma of the Colon: Diagnosis & Treatment
Frequently Asked Questions
1. What is a tubular adenoma?
A type of colon polyp that forms on the inner lining of the large intestine. It's benign (not cancer) but precancerous — it can slowly change into colon cancer over time if not removed. It's the most common adenoma found during colonoscopy.
2. Is a tubular adenoma cancer?
No. A tubular adenoma is benign — not cancer. But it's precancerous, meaning it has the potential to develop into adenocarcinoma (a type of cancer) over time if it's not removed.
3. How common are tubular adenomas?
About 1 in 3 adults over age 50 will develop at least one adenoma in their lives. Tubular adenomas are the most common type of adenoma found during colonoscopy.
4. What causes a tubular adenoma?
The exact cause isn't fully known. They develop when the lining of the colon grows faster than usual, forming extra tissue that becomes a polyp. Most start as tiny clusters of cells that gradually enlarge over many years.
5. What are the symptoms of a tubular adenoma?
Most tubular adenomas cause no symptoms at all. They're usually found during routine screening colonoscopy. Signs that warrant prompt evaluation (to rule out colon cancer) include blood in stool, new constipation or diarrhea, abdominal pain, and changes in stool shape or size.
6. What does "precancerous" mean?
The term precancerous means the growth isn't cancer now, but has the potential to slowly become cancer over many years if it's not removed. Tubular adenomas grow slowly, which is why screening and removal are so effective.
7. What is dysplasia?
Dysplasia means the cells are growing in an irregular pattern. Low-grade dysplasia = early or mild changes. High-grade dysplasia = more-serious precancerous growth requiring more-frequent monitoring. High-grade dysplasia is not cancer.
8. How is a tubular adenoma removed?
Through a procedure called polypectomy, performed during colonoscopy. A wire loop called a snare cuts the adenoma away. It's quick, generally painless, and done under sedation.
9. Does the polyp grow back after removal?
Once completely removed, the same polyp does not grow back. However, if cells are left behind (incomplete removal), it can regrow in the same location. New adenomas can also form over time, which is why follow-up colonoscopies matter.
10. When should I have my next colonoscopy?
It depends on your pathology findings: 1–2 small (<10 mm) tubular adenomas → 7–10 years; 3–4 small adenomas → 3–5 years; 5–10 small adenomas, any adenoma ≥10 mm, or villous/high-grade features → 3 years; more than 10 adenomas → 1 year.
11. What are the risk factors for tubular adenomas?
Age 50+, inflammatory bowel disease, family history of advanced polyps, personal history of polyps, smoking, 3+ alcoholic drinks daily, diabetes (50% increased risk), obesity, less healthy diet, lack of exercise, certain racial/ethnic backgrounds, and rare inherited syndromes (Lynch syndrome, FAP).
12. Does diabetes increase my risk?
Yes. Having diabetes increases polyp risk by 50% among all age groups.
13. What is the difference between a tubular adenoma and a villous adenoma?
Tubular adenomas have round, tube-shaped glands and carry the lowest cancer risk among adenomas. Villous adenomas have long, fingerlike projections and carry a higher risk of becoming cancer if left untreated. Tubulovillous adenomas show features of both and also have high risk.
14. What is a hyperplastic polyp?
A common, usually harmless polyp that's flat or saw-toothed on the surface. It's not considered precancerous and carries very low cancer risk. It's especially common in the rectum and sigmoid colon.
15. What does my pathology report mean?
The pathology report includes the polyp type (tubular adenoma = benign but precancerous), size and location, microscopic findings, dysplasia grade (low or high), margin status (negative = completely removed, positive = suspicious cells remain), high-risk features, and a follow-up recommendation for when to return for another colonoscopy.
16. What does "negative margin" mean?
The term negative margin means the edges of the removed tissue are free of unusual cells — the polyp was completely removed. A "positive margin" means suspicious cells remain at the edges.
17. Can a tubular adenoma turn into cancer?
Only if its cells continue to grow and change over many years without being removed. Once completely removed, the risk is very low. Large adenomas, those with high-grade dysplasia, or villous features are more likely to progress if left untreated.
18. Should I get a stool test or a colonoscopy?
Stool-based screening tests (such as multitarget stool DNA testing) can identify many large and most high-grade polyps. However, a positive stool test does not by itself indicate a polyp or cancer — a colonoscopy must be performed to evaluate anyone with a positive result. Regular colonoscopy screening with complete removal of all adenomas is the best prevention.
19. What lifestyle changes lower my risk?
The risk factors you can address include drinking fewer than 3 alcoholic drinks a day, quitting smoking, maintaining a healthy weight, exercising regularly, and eating a healthier diet. Your doctor may recommend these based on your individual profile.
20. Should I see a specialist?
You'll likely be referred to a gastroenterologist (digestive disease specialist), a colorectal surgeon, or a pathologist — depending on your findings and whether further treatment or surgery is needed.
References
Mayo Clinic Staff. Tubular adenoma of the colon: Symptoms and causes. Mayo Clinic. November 22, 2025. https://www.mayoclinic.org/diseases-conditions/tubular-adenoma-of-the-colon/symptoms-causes/syc-20592117
Mayo Clinic Staff. Tubular adenoma of the colon: Diagnosis and treatment. Mayo Clinic. November 22, 2025. https://www.mayoclinic.org/diseases-conditions/tubular-adenoma-of-the-colon/diagnosis-treatment/drc-20592128
Yu F, Guo Y, Wang H, et al. Type 2 diabetes mellitus and risk of colorectal adenoma: a meta-analysis of observational studies. BMC Cancer. 2016;16:642. PMID 27535548. https://doi.org/10.1186/s12885-016-2685-3
Enwerem N, Cho MY, Demb J, et al. Systematic review of prevalence, risk factors, and risk for metachronous advanced neoplasia in patients with young-onset colorectal adenoma. Clin Gastroenterol Hepatol. 2021;19(4):680-689.e12. PMID 32428708. https://doi.org/10.1016/j.cgh.2020.04.092
Medical disclaimer
This article is for general educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis, treatment decisions, and personal health guidance. If you notice blood in your stool, changes in bowel habits, or abdominal pain, seek prompt medical evaluation.
Comments